Chronic patellar tendinosis (jumper's knee) is a common problem among athletes. Conservative treatment is successful in most of the cases including, among others, the use of nonsteroidal anti-inflammatory drugs, local cryotherapy, eccentric muscle training, limitation of sports activity, and local infiltration. In approximately 10% of conservatively treated patients, conservative treatment fails and surgery is required. Different open and arthroscopic surgical techniques have been described in the literature. The presented all-arthroscopic surgical technique for the treatment of chronic patellar tendinosis includes debridement of soft tissue at the lower patellar pole and resection of the bony lower patellar pole. It leads to excellent clinical results comparable to described open treatment and provides the benefits of a minimally invasive and safe procedure with a faster recovery and return to sporting activities after surgery. An additional bony resection in case of a prominent lower patellar pole does not lead to a significant extension of the operation time and may avoid a relapse or treatment failure in selective cases. Therefore, arthroscopic treatment such as the presented technique may be the preferred method for surgical treatment of chronic patellar tendinosis.